Acylated derivatives of high molecular weight copolymers



mama Mar. 1, 1050 ACYL ATED DERIVATIVES 0F HIGKMO- LECULAI WEIGHT OOPOL Eugene Lieber, New York, N. Y., and

Smyers, Westileld, N. 1., aslignors William H. to Standard Oil Development Company, a corporation of Delaware No Application April 4, 1045, Serial No. 580,026

11 Claims. (cl. 260-231 This invention relates to novel chemical prodnets and to methods of preparing and using same.

More particularly it relates to making and using ecylated derivatives of high molecular weight copolymers, particularly hydrocarbon copolymers such as the styrene-isobutylene copolymers, styrene-diolefln copolymers, styrene-acryloniirile copolymers. i

Copolymers of styrene-isobutylene, and more generally copolymers of aliphatic oleflns with polymerimble cyclic compounds, are disclosed in U. 8. Patent 2,274,740. The general method of preparing such copolymers is also disclosed therein and consists essentially in carrying out the copolymerization of the mixed reactants at a temperature below 0' C. such as --10 0., -50 0., il0 6., -100 6., or even lower, in the presence of an active halide polymerization catalyst, and preferably in the presence of an inert, volatile organic liquid serving as solvent and refrigerant.

Insteadof styrene, other polymerisable cyclic material may be used such as alphamethyl styrene, paramethyl styrene, alphamethvl paramethyl styrene, indene, terpene, coumarone, etc., as well as copolymers of indene and coumarone.

Instead of isobutyiene, other isoleiins may be used such as isoarnylene, particularly methyl-2 butene-l, iso-octylene etc... as well as other aliphatic oleilns such as propylene and normal butylenes, and other oleflnic material such as unsaturated nitriles for example, acrylonitrile etc, Dioletlns may be used such as butadiene, isoprene, dimethyl-butadiene, cyclopentadiene, hexadiene, etc. Halogenated dioleilns may be used such as chlorobutadiene.

The proportions in which the styrene 6r other polymerizable cyclic material and the isobutylene or other aliphatic oleiin or dioleflnic material may be copolymerized may vary over a wide mine from 1% to 50% or 90% or even 99%, preferably about 1% to 80%, of the polymerizable cyclic constituent. In fact, an even smaller amount of such cyclic material may be used such as even 0.1% or less, it being sufllcient to merely have 1 or 2 molecules of the styrene or other polymerisable cyclic material combined into a relatively long chain of isobutylene or other aliphatic olefin, the aromatic nucleus of the styrene serving as a chemical handle by which the high molecular weight resultant copolymer may be subjected to the subsequent acylatlon reaction accoi'ding to the present invention.

For convenience and brevity, the above described copolymer of a cyclic polymerisable materialand anoleflnwillbereferredtoasacycalkene copolymer. The specific type oi copoiymer made from styrene and isobutylene will similarly be referred to for brevity as stybutene. The invention will be illustrated as applied particularly to stybutene, although it is not to be limited thereto.

The copolymer to be used may also be a tripolymer of a polymerizable cyclic compound, an oleiinic compound and a small amount, e. g. 0.1% to 30%, preferably 0.5% to 10% or a diole-,

' fin, e. g., isoprene, butadiene, etc. One example of such a tripolymer is one comprising 50%" iso-j butyiene, 47% styrene and 3% isoprenein the combined state.

The acylating agent to be used according to' this invention may be selected from a wide variety of materials having the general formula mcoxm where R is a hydrocarbon group, x is halogen and n is an integer of l to 3, preferably 1 to 3, including acylatins agents which are commercially available as well as others which may be made for the present purposes. These acylating agents may be either in the form of the acyl halide, preferably acyl chloride, or others such as acyl bromide. They are preferably derived from fatty acids in which the hydrocarbon radical comprises five or more carbon atoms and preferably at least five aliphatic carbon atoms, as for instance in palmitic acid, stearic acid, phenyl stearic acid, linoleic acid and dilinoleic acid. They may also be derived from such acids as maleic acid, succinic' acid, adipic acid, sebacic acid, cyclohexane carboxylic acid and phthalic acid as well as acyl halides derived from other fatty acids or mixed fatty acids as derived from iatty oils such as soybean oil, corn oil, etc. Naphthenyl halides, derived from petroleum naphthenic acids may also be used. Unsaturated acylating agents may also be used, such as; oleyl chloride, linoleyl chloride, di-linoleyl chloride, etc., so the resulting product can be vulcanized if so desired.

Besides the acylating agents of the type R(COX),. we can also use agents of the type R(SOmX) n where R, X and n have the same significance as before and m is an integer whose value is l or 2, preferably 2. These materials are commonly known as suli'onyl halides and of these the sulfonyl chlorides are preferred. Particularly valuable are the sulfonyl chlorides derived from paraflln wax, which may be designated by the formula wax-SOa-Cl escapes These materials are readily prepared by, reacting parailln wax with a mixture 01' gaseous sulfur dioxide and chlorine. Other suli'onyl chlorides which can be used may be mentioned: cyclohexyl suionyi chloride, octadecyl-disulronyl chloride, phenyl-stearyl sulionyl chloride:

i. e., a combined sulronyi and acyl chloride.

If the stybutene or other copolymer is made with a relatively high content 01' combined cyclic constitutent such as 20% or 30% or more 01' combined styrene, it is preferable to use an acylating agent having at least 5 aliphatic carbon atoms and preferably at least 10, stearyl chloride being relation to the copolymer, may vary over a fairly wide range, depending partly on the proportion of combined cyclic, especially aromatic, constituent in the copolymer, and upon the molecular weight 01' the acylating agent, but normally about 50 to 200 parts by weight and prei'erably 50 to 100 parts by weight of acylating agent should be used per 100 parts of copolymer. Although the proportions by weight will oi course depend upon the molecular weight of the acylatlng agent as well as that 01' the copolymer, generally about 50 to 150 parts by weight of acylating agent will be satisfactory tor 100 parts by weight of the copolymer.

The acylation is preferably carried out in the presence of a Friedel-Craits catalyst such as aluminum chloride, boron fluoride, ZnCl-z, etc. The amount of this catalyst required is generally about 0.5 to 2.0 mol per mol of acylating agent. The acylation is also preferably carried out in the presence of a solvent such as tetrachlorethane, a refined petroleum naphtha, o-dichlorohenzene, ethylene dichloride, nitropropane, etc.

The amount of such solvent to be used, is preferably about 3 to volumes, preferably about 1 to 5 volumes or solvent per volume of mixed reactants, i. e., copolymer and acylating agent. The temperature required for the acylating reaction depends partly upon the reactivity of the particular acylating agent used and upon the amount of solvent and the proportion of combined cyclic constituent in the copolymer, but normally will range from room temperature to about 300 F., and generally from about 150 F. to 250 F.

After the acylation reaction has been completed, as evidenced by the substantial cessation of hydrogen chloride evolution even with further heating, the reaction mixture may be cooled e. g., to room temperature or so, and isthen preferably diluted with additional solvent and then residual aluminum chloride or other catalyst is destroyed by adding water, alcohol, aqueous hydrochloric acid or aqueous caustic soda, etc. Besulting catalyst sludge is then withdrawn and the solvent extract containing the desired acylated copolymer may be washed repeatedly until final wash water shows no test for acid with litmus paper. The acylated copolymer may, ii desired, be used in solution in the solvent it thus recovered, or the solvent may be removed by distillation or other suitable means so as to recover the acylated copolymer per se. 11' it is desired to use the acylated copolymer eventually in solution in a mineral lubricating oil, a small amount of such oil may be added to the volatile solvent solution before evaporation of the volatile solvent, so that after such evaporation, the residue will consist of a mineral lubricating oil concentrate oi the acylated copolymer, containing tor instance, about 15% to 50% of such acylated copolymer.

The product or this invention, namely the acylated cycalkene copolymer is thus a high molecular weight polymeric linear type copolymer chain and having a molecular weight of at least 2,000 having attached thereto one or more acyl or suli'onyl groups, tree from any interlinking in case the acylating agent used is a monobasic acylating agent, e. g., stearyl chloride, or having two or more copolymer molecules interlinked by means of the acylating agent in case a dibasic acylating agent is used such as phthalyl chloride, sebacyl chloride and the like. The molecular weight of the final product will accordingly be only slightly more than that or the original copolymer it no interllnking has taken place, but may be 2, 3 or more times as great it interlinking has been eiiected. This product, which generally ranges from a soft plastic to a hard waxy or resinous solid has both viscosity index improving and pour depressing characteristics, which make the product a valuable additive for mineral oils such as lubricating oils or even the more fluid oils such as a gas oil, kerosene, or even naphtha which may be useful for low temperature hydraulic oil purposes.

The product may also be sheeted into self-sustaining films or moulded, or may be compounded with paraffin wax, asphalt, various natural and synthetic resins, e. g., shellac, coumarone-indene resins, phenol-formaldehyde resins, etc. and plastics such as cellulose acetate, benzyl cellulose,

, polystyrene, etc., natural rubbers, synthetic rubbers such as butadiene-styrene emulsion conchmer, e. g., the one marketed commercially as Bum S butadiene-acrylonitrile copolymer, lowtemperature isobutylene lsoprene copolymer, polyisobutylene, etc.

This new product may also be chlorinated, oxidized, hydrogenated, reacted with chlorinated paraffin wax, suli'urized with sulfur chloride or sulfur, or reacted with P285, etc.

The objects, advantages, and details of the invention will be better understood from a consideration of the following experimental data.

Example 1 25 gms. of a stybutene having a combined styrene content of about 50% and made at a temperature 01 about 103 0., in three volumes oi methyl chloride per volume of mixed reactants. and having an average molecular weight of about 30,000 and an intrinsic viscosity oi about 1.0, was

AlCh destroyed by addition of an alcohol-water mixture. The residue which amounted to 35 grams was a viscous, waxy-like, resinous material.

The pour depressing potency oi this stearylated stybutene was tested by blending it in an oil comprising 90% by volume or a Pa. neutral lubricating oil base stock and by volume oi a Pa. bright stock, which mixed base stock had a pour point of +30 B. when the acylated copolymer was added in various concentrations, the following pour points were obtained:

Pour '1'. Original oil "I +80 Original oil +1% product Original oil product +10 Original oil product 5 being also shown:

Viscosity (sec. Beybclt at Pom V. I l 100 F. I 210 F.

Original Oil 141 42. 7 101 130 Original Oil +2.5 Product. 160.4 44.7 112 II Original Oil +5. 0 Product. 185. 7 47.0 117 +10 1 Viscosity index. 7

These data indicate that the stearylated stybutene has both viscosity index improving and pour depressing properties; in other words, pour depressing properties have for the first time been imparted to the long copolymer molecules, and this, surprisingly, without destroying the viscosity index improving characteristics of the latter.

Example 2 25 grams of a stybutene having a combined styrene content of about 80%, made at a temperature of -23 0., and having an average molecular weight of about 3,000, was dissolved in 125 cc. carbon tetrachloride. 86 grams of anhydrous Aicla was added and the temperature ad- ;iusted to 110 F. While stirring 150 grams of stearyl chloride was added to the reaction ture over a period of 10 minutes. After the ad 1- tion of the stearyl chloride the reaction temperature was increased to 125 F. and maintained thereat for 5 hours. At the end of this time, the reaction mixture was cooled and diluted with 500 cc. additional solvent and the A101: destroyed by addition of an alcohol-water mixture. After settling and removal of the aqueous sludge layer, 100 grams of a mineral oil (43.4 SSU via/100 F.) was added, in order to facilitate recovery oi the polymer, and the solvent removed by a vacuum distillation at mm. Hg pressure and 220 F. A yield of 215 grams, comprising an oil solution of the stearylated-stybutene" was obtained. The pour depressant potency was tested by blending Q the product. obtained as described above. in a wax-containing lubricating oil and determining the pour point of the resulting blends by the standard A. 8. '1. ll. procedure. The following resultswere obtained. the concentrations being expressed in tenns oi actual stearylated-etybutenc:

A. B. '1. M. Pour goi Per cent Additive The viscosity index was determined, the results being as follows:

Sec. Haybolt Univ. Viscosity Viscosity at index Original on 43.4 101 Original 0il+5% product 47.0 UK

These data show that the stearylated stybutene made by Example 2 had even better pour depressing characteristics than that in Example 1, and also had substantial viscosity index improving characteristics, although the particular stybutcne copolymer used as starting material did not have as good viscosity index improving characteristics as might be obtained with higher molecular weight stybutene made at lower temperature and with a lower combined styrene content.

Emmpie 3 An fllustration of the application 01' the invention to such higher molecular weight conolymers is to react a stybutene having a combined styrene content of about 5%. made at a tem rature of i03 C., and having a molecular we t of about 80.000, with an acylating agent such asithe stearyl chloride used in Examples 1 and 2 or -with a dibasic stearylatlng agent such as phtiialyl chloride, sebacyl chloride, dilinoleyl chloride, etc.

The invention may also be carriedmut by reacting the copolymer with other treating agents having the general formula RiYOXia' where X is halogen, Y is C, B. or SO, and n is;1 to 3; for instance wax suli'onyl chloride may iised, having the formula 8(80201) a. where R a paraiiin wax molecule and n has an average value of from 1 to 2.

It is not intended that this invention be limited to the specific materials which have been given merely for the sake of illustration, but only by the appended claims in which it is intended to claim all novelty inherent in the invention. as well as all modifications coming within the scone and spirit of the invention.

We claim:

1. Process according to claim 7 using a monobasic acylating agent.

2. Process according to claim 'I using stearyl chloride as acylating agent.

8. Process according to claim 7 using a dibaeic acylating agent. p

4. Process according to claim 7 usin sebacyl chloride as acylating agent.

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aluminum chloride as catalyst and in the presence of an inert non-aqueous solvent, hydrolyzing and removing residual catalyst and subjecting the reaction products to distillation under reduced pressure to obtain the desired stearyl atyrene-isobutylene copolymer as distillation residue.

7. The process which comprises acylating a substantially linear styrene-isobutylene copolymer having a molecular weight or from 3,000 to 90,000 and having a styrene content of from 1- by weight, with an aliphaticactylating agent having the general formula R(COX)., X being a halogen. n being a number from 1 to 2 and and It being an aliphatic hydrocarbon group of at least 5 and not more than 30 carbon atoms, said acylation being carried out by combining 50 to 150 parts by weight of acylating agent with 100 parts by weight of the copolymer in the presence of a lriedei-Crafts catalyst.

8. A process according to claim 6 wherein the styrene content or the oopolymer is from 40% to 6096 by weight.

9. A product according to claim 10 wherein the styrene content 01' the copolyin'er is troni 40% to me by weight.

10. An acylated substantially linear copolymer of styrene and isobutylene, said copolymer having a styrene content of from 1 to 00% by weight and a molecular weight, before acyla'ticmot from 8,000 to 30,000, said acylating radical having the general formula R(CO)n-, n being a number from 1 to 2 and. R b i an aliphatic hydrocarbon group of from 5 to 30 carbon atoms.

11. A stearylated substantially linear styrenelsobutylene copolymer, said copolymer having a styrene content of from 1 to by weight and a molecular weight, before stearylation, of from 9,000 to 30,000.

WILLIAM H. SMYERS.

REFERENCES CITED 'The following references are of record in the tile of this patent:

UNITED STATES PATENTS Number Name Date 2,150,156 Dietrich Mar. 14, 1939 2,186,359 Britten et a1. "Jan. 9, 1940 2,197,709 Ralston et al. Apr. 16, 1940 2,213,423 Wiezevich' Sept. 2, 1940 2,274,749 Smyers Mar. 2, 1042 2,288,319 Mikeska et 'al. June 30, 1942 2,352,280 Mikeska June 27, 1944 

6. THE PROCESS WHICH COMPRISES REACTING A SUBSTANTIALLY LINEAR STYRENE-ISOBUTYLENE COPOLYMER HAVING AN AVERAGE MOLECULAR WEIGHT OF 3,000 TO 30,000 AND A STYRENE CONTENT OF 20-60% BY WEIGHT WITH STEARYL CHLORIDE IN THE PRESENCE OF ALUMINUM CHLORIDE AS CATALYST AND IN THE PRESENCE OF AN INERT NON-AQUEOUS SOLVENT, HYDROLYZING AND REMOVING RESIDUAL CATALYST AND SUBJECTING THE REACTION PRODUCTS TO DISTILLATION UNDER REDUCED PRESSURE TO OBTAIN THE DESIRED STEARYL STYRENE-ISOBUTYLENE COPOLYMER AS DISTILLATION RESIDUE. 